PHP字符串加密解密

 

/**
 * 字符串加密、解密函数
 * @param   string $string 字符串
 * @param   string $operation ENCODE为加密，DECODE为解密，可选参数，默认为ENCODE，
 * @param   string $key 密钥：数字、字母、下划线
 * @param   int $expiry 过期时间
 * @return  string
 */
function str_crypt($string, $operation = 'ENCODE', $key = '', $expiry = 0)
{
    $key_length = 4;
    $key = md5($key != '' ? $key : KEY);
    $fixedkey = md5($key);
    $egiskeys = md5(substr($fixedkey, 16, 16));
    $runtokey = $key_length ? ($operation == 'ENCODE' ? substr(md5(microtime(true)), -$key_length) : substr($string, 0, $key_length)) : '';
    $keys = md5(substr($runtokey, 0, 16) . substr($fixedkey, 0, 16) . substr($runtokey, 16) . substr($fixedkey, 16));
    $string = $operation == 'ENCODE' ? sprintf('%010d', $expiry ? $expiry + time() : 0) . substr(md5($string . $egiskeys), 0, 16) . $string : base64_decode(substr($string, $key_length));

    $result = '';
    $string_length = strlen($string);
    for ($i = 0; $i < $string_length; $i++) {
        $result .= chr(ord($string{$i}) ^ ord($keys{$i % 32}));
    }
    if ($operation == 'ENCODE') {
        return $runtokey . str_replace('=', '', base64_encode($result));
    } else {
        if ((substr($result, 0, 10) == 0 || substr($result, 0, 10) - time() > 0) && substr($result, 10, 16) == substr(md5(substr($result, 26) . $egiskeys), 0, 16)) {
            return substr($result, 26);
        } else {
            return '';
        }
    }
}

 

来源：oschina

链接：https://my.oschina.net/mynotes/blog/4313826